After some research,
it seems the MOD Dep actually used different 5513 style bezels on these particular 6538 watches. the insert looks good, the pearl is junk obvi..

the case is legit and so are the fixed lug bars.. if the fixed bars were added after the fact, then that means at some point this watch had a bracelet for several years, but there are no marks under the lugs that show signs of SEL wear marks..

the dial may look like a later service tritium dial but its not. it is original to the watch as thats what the T dials looked like that they used at the time. the hands have been replaced for sure tho.

I flew literally half way around the world a couple months ago to buy this watch ... Unfortunately it is missing its unique German silvered nickel bezel and someone has slapped on a completely wrong 5513 bezel ... I passed as this alone can take 20-30k off the value and massively reduces the desireability and appeal of what is already a highly specialised watch ...

The dial is a correct burford dial , a non Rolex manufactured dial that these watches were switched to in the early 60s by the mod ...

I flew literally half way around the world a couple months ago to buy this watch ... Unfortunately it is missing its unique German silvered nickel bezel and someone has slapped on a completely wrong 5513 bezel ... I passed as this alone can take 20-30k off the value and massively reduces the desireability and appeal of what is already a highly specialised watch ...

The dial is a correct burford dial , a non Rolex manufactured dial that these watches were switched to in the early 60s by the mod ...

I flew literally half way around the world a couple months ago to buy this watch ... Unfortunately it is missing its unique German silvered nickel bezel and someone has slapped on a completely wrong 5513 bezel ... I passed as this alone can take 20-30k off the value and massively reduces the desireability and appeal of what is already a highly specialised watch ...

The dial is a correct burford dial , a non Rolex manufactured dial that these watches were switched to in the early 60s by the mod ...

I flew literally half way around the world a couple months ago to buy this watch ... Unfortunately it is missing its unique German silvered nickel bezel and someone has slapped on a completely wrong 5513 bezel ... I passed as this alone can take 20-30k off the value and massively reduces the desireability and appeal of what is already a highly specialised watch ...

The dial is a correct burford dial , a non Rolex manufactured dial that these watches were switched to in the early 60s by the mod ...

Thanks Jed for sharing this with us as your expertise is always appreciated.

it is missing its unique German silvered nickel bezel and someone has slapped on a completely wrong 5513 bezel ... I passed as this alone can take 20-30k off the value and massively reduces the desireability and appeal

WOW!! A 30 grand bezel.

Know I now I'm out of my depth!!!

This is all great info, I went through 4 highly rated reference books and you guys have produced 100% more info than I found in these books.

Is there a reference area by model number in the forums to collate such invaluable information? This knowledge is gold-dust.

Agree with Jed, all ok (and authentic), correct MOD redial from early/mid 1960s, but a later 5512/3 bezel and insert which really impacts value on an A/6538, and real shame that the military numbering has been erased from the back...

The 5513/7 bezel is standard - same as a normal civilian 5513 - though obviously with a different insert.

The a6538 bezel is IMHO the missing link , it's in effect a handmade prototype of the bezel design that would become synonymous with all subs going forward from the 5512 intro in 1959.

The British navy divers / mod use of Rolex dive watches featured heavily in the advertising material of the time and there've cab be no doubt there were close ties . The previous coin edge bezel design we know from the 6200 to the 5510 is a bugger to turn at best of times on dry land ... Imagine doing it underwater !!! The mod had received initially. Batch of standard 6538 watches , but only a couple of years later they received this batch of unique design A6538 ... I'd guess partially as a field test for the new bez design .. A result of their initial feedback ? .. Who knows for sure but if they were being used as a real life test group then possibly...

For me the significance of this model as the missing link between the old sib look and the current sun look can't be overstated ...

And once again , I'll point out that if Ian Fleming researched what watch the royal navy gave its operatives ,, or even just picked up a piece of Rolex advertising at the time ... You are looking at the true inspiration for bonds watch - not some explorer that the novice would jump to conclude was described in the few clues given the book could refer to.

I flew literally half way around the world a couple months ago to buy this watch ... Unfortunately it is missing its unique German silvered nickel bezel and someone has slapped on a completely wrong 5513 bezel ... I passed as this alone can take 20-30k off the value and massively reduces the desireability and appeal of what is already a highly specialised watch ...

The dial is a correct burford dial , a non Rolex manufactured dial that these watches were switched to in the early 60s by the mod ...

This vender is being somewhat "loose" with the truth then jed as im sure you would have advised him/her/them that the bezel was non original to the watch -
Im sure the vender would justify their discription by stating - THE BEZEL IS AN ORIGINAL ROLEX!!!